Slight Increases in the Disease Activity Index and Platelet Count Imply the Presence of Active Intestinal Lesions in C-reactive Protein-negative Crohn's Disease Patients

Objective Although the serum C-reactive protein (CRP) level may, to some extent, predict the disease activity in patients with Crohn's disease (CD), it is not always elevated during periods of disease activity. This study aimed to identify factors predicting the presence of active intestinal lesions in CD patients without an elevated CRP level. Methods CD patients in whom the presence or absence of active intestinal lesions was evaluated using endoscopic and/or radiologic modalities were divided into two groups based on a negative (< 3 mg/L) or positive (>= 3 mg/L) CRP level. The correlations between the presence of active intestinal lesions and various clinical variables, including the Crohn's Disease Activity Index (CDAI), leukocyte and platelet counts and hemoglobin, serum albumin and CRP levels, were determined in the CRP-negative patients. Results Of the 128 patients examined, 70 had a negative CRP status, approximately half of whom had active intestinal lesions. The multivariate analysis revealed a CDAI of > 100 and platelet count of > 33x10(4)/mu L to be significant predictive factors for the presence of active lesions in the CRP-negative patients [CDAI > 100, odds ratio (OR) = 5.55; 95% confidence interval (CI), 1.80-18.74, platelet count > 33x10(4)/mu L, OR = 5.94; 95% CI, 1.34-28.87]. The sensitivity of fulfillment of either criterion for the presence of active intestinal lesions was 83%, while the specificity of fulfillment of both criteria was 94%. Conclusion A relatively low CDAI and platelet count were identified as predictive markers of the presence of active intestinal lesions in CRP-negative CD patients. These results suggest that symptoms and laboratory data should be evaluated very carefully in such patients.